[MPlayer-dev-eng] configure vs #undef

[Roberto Togni]

On Mon, 21 Aug 2006 14:51:23 +0200
Diego Biurrun <diego at biurrun.de> wrote:

> Currently configure sets "#define FOO" if a test succeeds and if it
> fails it sets "#undef FOO" in config.h.  I wonder if this is necessary.
> AFAICT we only depend on defined and not on undefine things.
> 
> I'm tempted to remove all the #undef, which should get rid of 250 or
> more lines in configure.  Am I overlooking something?
> 

They are useful when you debug a problem with some user: if you ask him
to grep configure for some label, he will get a result and will tell
you if the label is defined or undefined. If you only have the defines
and the user reports that he got no match, you will never know if the
label is undefined or if he did something wrong while grepping for it.

Ciao,
 Roberto